The present invention comprises a new and distinct cultivar of Chrysanthemum botanically known as Chrysanthemum morifolium, and referred to by the variety name ‘Grace Time Pearl Improved.’ ‘Grace Time Pearl Improved,’ identified as 20911-26, was discovered as a whole plant mutation found in a controlled cultivated planting of the variety ‘Grace Time Pink’ (U.S. Plant patent application Ser. No. 60/524,339). The new variety ‘Grace Time Pearl Improved’ has been asexually reproduced by vegetative cuttings in Chichester, West Sussex, United Kingdom and the distinguishing characteristics are retained through successive generations of asexual reproduction.